Diagnostic device, diagnostic system, diagnostic method, and non-transitory computer-readable medium

A diagnostic device includes an acquisition unit, first and second measurement units, a generation unit, and a guidance unit. The acquisition unit accepts a produced sound as input and acquires sound information. The first measurement unit measures a distance from a standard position. The second measurement unit measures a change in orientation from a standard state. The generation unit generates appropriate position information, the appropriate position information being the distance from the standard position to the diagnostic device measured by the first measurement unit, and the change in orientation from the standard state measured by the second measurement unit. The guidance unit uses the appropriate position information to guide the diagnostic device to an appropriate position when acquiring the sound information.